4a the larva lives in a corridor (usually in dead plant material) with two openings, in which it maintains a water current by constant sinuous movements. It lives on detritus particles brought by the current. These larvae are no miners, and are not discussed here. Hering (1957a) keys the species known up to then.

5 Mandible with 1 tooth, no anterior spiraculum: Hydrellia (Ephydridae). The larvae of several species make irregular, very shallow mines, both in the floating and in the submerged leaves. The larvae are not described, and the mines are not sufficiently diagnostic, so only rearing can lead to an identification. The larvae pupate in the mine, breeding therefore poses not many problems. The key of the adult flies that follows is entirely derived from Hering (1957a) => 6